To meet the demand for natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a completion system that includes a high pressure wellhead assembly through which the resource is extracted. These completion systems may include a wide variety of components, such as various casings, hangers, valves, fluid conduits, and the like, that control drilling and/or extraction operations.
One type of completion assembly includes a high pressure wellhead housing (“wellhead”) with one or more strings of casing supported by casing hangers in the wellhead. Attached to the wellhead may be a tubing spool with a tubing hanger secured to a string of tubing that lands in the tubing spool above the wellhead. The tubing spool may have a plurality of vertical passages that surround a vertical bore. The vertical fluid passages provide access through the tubing spool for hydraulic fluid or electrical lines to operate and control equipment located downhole, such a safety valves or chemical injection units. Electrical and/or hydraulic control lines may extend alongside the outside of the tubing to control downhole valves, temperature sensors, and the like. A production tree is then installed on top of the tubing spool. The production tree has a vertical bore that receives upward flow of fluid from the tubing string and wellhead.
A production tree usually contains at least two valves enabling or preventing flow from the well into a flow line. It is known to have two gate valves in series on a horizontal branch of the tree for this purpose: the first may be called the production master valve (PMV), and the second may be called the production wing valve. Further, there might be a choke valve controlling the flow from the tree into the flow line.
It might be desirable to measure the production out of the production tree. For this purpose one man might place a multiphase or wet gas flow meter in the process flow line somewhere between the wellhead and a commingling point.